Extract rackup code + tests into separate gem.

lib/rack/handler.rb

@@ -2,86 +2,22 @@
 
 module Rack
   # *Handlers* connect web servers with Rack.
-  #
-  # Rack includes Handlers for WEBrick and CGI.
-  #
-  # Handlers usually are activated by calling <tt>MyHandler.run(myapp)</tt>.
-  # A second optional hash can be passed to include server-specific
-  # configuration.
   module Handler
     @handlers = {}
 
-    def self.get(server)
-      return unless server
-      server = server.to_s
-
-      unless @handlers.include? server
-        load_error = try_require('rack/handler', server)
-      end
-
-      if klass = @handlers[server]
-        const_get(klass)
-      else
-        const_get(server, false)
-      end
-
-    rescue NameError => name_error
-      raise load_error || name_error
-    end
-
-    # Select first available Rack handler given an `Array` of server names.
-    # Raises `LoadError` if no handler was found.
-    #
-    #   > pick ['puma', 'webrick']
-    #   => Rack::Handler::WEBrick
-    def self.pick(server_names)
-      server_names = Array(server_names)
-      server_names.each do |server_name|
-        begin
-          return get(server_name.to_s)
-        rescue LoadError, NameError
-        end
+    # Register a named handler class.
+    def self.register(name, klass)
+      if klass.is_a?(String)
+        warn "Calling Rack::Handler.register with a string is deprecated, use the class/module itself.", uplevel: 1
+
+        klass = self.const_get(klass, false)
       end
 
-      raise LoadError, "Couldn't find handler for: #{server_names.join(', ')}."
-    end
-
-    RACK_HANDLER = 'RACK_HANDLER'
-
-    SERVER_NAMES = %w(puma falcon webrick).freeze
-    private_constant :SERVER_NAMES
-
-    def self.default
-      if rack_handler = ENV[RACK_HANDLER]
-        self.get(rack_handler)
-      else
-        pick SERVER_NAMES
-      end
-    end
-
-    # Transforms server-name constants to their canonical form as filenames,
-    # then tries to require them but silences the LoadError if not found
-    #
-    # Naming convention:
-    #
-    #   Foo # => 'foo'
-    #   FooBar # => 'foo_bar.rb'
-    #   FooBAR # => 'foobar.rb'
-    #   FOObar # => 'foobar.rb'
-    #   FOOBAR # => 'foobar.rb'
-    #   FooBarBaz # => 'foo_bar_baz.rb'
-    def self.try_require(prefix, const_name)
-      file = const_name.gsub(/^[A-Z]+/) { |pre| pre.downcase }.
-        gsub(/[A-Z]+[^A-Z]/, '_\&').downcase
-
-      require(::File.join(prefix, file))
-      nil
-    rescue LoadError => error
-      error
+      @handlers[name] = klass
     end
 
-    def self.register(server, klass)
-      @handlers[server.to_s] = klass.to_s
+    def self.[](name)
+      @handlers[name]
     end
   end
 end